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At least 19 recordsLinked to original sources

Visuo-spatial short-term recognition memory and learning after temporal lobe excisions, frontal lobe excisions or amygdalo-hippocampectomy in man.

Three groups of neurosurgical patients with temporal lobe excisions, frontal lobe excisions or unilateral amygdalo-hippocampectomy were assessed on a computerized battery of tasks designed to investigate visuo-spatial short-term recognition memory and learning. A double dissociation is reported between deficits of pattern recognition memory and spatial recognition memory which were observed in the two posterior groups and frontal lobe patients, respectively. In addition, both the temporal lobe and amygdalo-hippocampectomy patients were also impaired on a delayed matching-to-sample paradigm whilst frontal lobe patients performed at an equivalent level to controls. Finally, whilst the impaired performance of the three groups was indistinguishable on a test of paired-associate learning, quite different patterns of deficit were observed on a test of spatial working memory. These results are discussed with reference to recent suggestions that visual recognition memory is mediated by a neural system which includes, as major components, the inferotemporal cortex, the medial temporal lobe structures and particular sectors of the frontal lobe, and are compared to previous findings from patients with idiopathic Parkinson's disease and dementia of the Alzheimer type.

Adult↗

Planning impairments in frontal lobe dementia and frontal lobe lesion patients.

Patients with frontal lobe brain damage are reportedly impaired on tasks that require plan development and execution. In this study, we examined the performance of 15 patients diagnosed with frontal lobe dementia and 14 patients with focal frontal lobe lesions on the Tower of London planning task. Patients with frontal lobe dementia committed a significantly higher number of rule violations, made more moves, and demonstrated longer solution time latencies compared to their matched controls. Patients with frontal lobe lesions demonstrated significantly delayed solution times and also made more moves compared to their matched controls. Frontal lobe lesion patient performance suggests an impairment in execution-related processes, while frontal lobe dementia patients appear to be impaired in both plan development and execution. Despite these findings, the identification of a specific cognitive impairment that induces these planning problems remains elusive.

Adult↗

Memory function in focal epilepsy: a comparison of non-surgical, unilateral temporal lobe and frontal lobe samples.

Three well-matched groups of non-surgical, pharmacologically controlled epileptic patients with unilateral seizure foci in either the left temporal lobe, the right temporal lobe or a frontal lobe, and a normal control group were compared on several verbal and non-verbal memory tasks. Results revealed significant impairment of verbal memory in left temporal epileptic subjects, and significant impairment of non-verbal, visual memory in right temporal epileptic subjects. Seizure patients with unilateral frontal lobe foci did not differ from the control sample on any measure. Results support previous research which emphasizes the importance of temporal lobe systems in memory function. The findings are discussed with regard to the nature and specificity of the observed deficits.

Adolescent↗

Frequency judgements of abstract designs by patients with diencephalic, temporal lobe or frontal lobe lesions.

Patients with diencephalic, temporal lobe or frontal lobe lesions were compared with healthy controls on a frequency judgement task. The three patient groups were disproportionately impaired at estimating how often a series of abstract designs had been presented relative to controls. Diencephalic and temporal lobe patients did not differ from each other. It is argued that the results may reflect a 'core' memory deficit in the temporal lobe patients. The impairment in the frontal patients may reflect their difficulty in making an organised search in memory for multiple traces of an item, while the deficit shown by the diencephalic patients (particularly those with Korsakoff syndrome) may be due to the combined effects of a generally poor memory and superimposed frontal pathology.

Adult↗

Assessing frontal lobe behavioral syndromes with the frontal lobe personality scale.

Reliability and construct validity are reported for the Frontal Lobe Personality Scale (FLOPS), a brief neurobehavior rating scale. The FLOPS Family form was completed by family members of 24 frontal lobe brain-damaged patients, 15 non-frontal lobe brain- damaged patients, and 48 healthy controls. Intrascale reliability was demonstrated (internal consistency.96; split half.93). Validity studies of frontal lobe patients post-lesion compared to their pre-lesion status, to healthy controls, and of frontal lobe patients pre- and post-lesion compared to non-frontal lobe patients pre- and post-lesion, indicated that frontal lobe patients post-lesion showed significantly more frontal behavior than (a) pre-lesion frontal lobe patients, (b) healthy controls, and (c) post-lesion non-frontal lobe patients. The FLOPS appears to be useful for quantifying frontal lobe behavior in clinical and research settings.

Adult↗

Frontal lobe tasks do not reflect frontal lobe function in patients with probable Alzheimer's disease.

Thirty-one patients with probable Alzheimer's disease (AD) according to NINCDS-ADRDA criteria were psychometrically tested with various frontal lobe tasks. The results were correlated with regional cerebral glucose metabolism (rCMRG1) as measured by positron emission tomography of 18F-2-fluoro-2-deoxy-D-glucose. RCMRG1 of frontal functional-anatomically defined regions was not linked to the performance seen in frontal lobe testing. The majority of the frontal lobe tasks showed a high correlation to severity of dementia that was related to rCMRG1 of the temporo-parietal cortex. There were high intercorrelations of frontal lobe test scores to other tests. Thus, these tasks seem to measure nonspecific cognitive changes in AD patients.

Aged↗

Frontal lobe and frontal-striatal substrates for different forms of human cognitive flexibility.

Frontal lobe and basal ganglia lesions have been associated with similar cognitive impairments, although their specialized roles in behavior are likely to be different. We examined whether these structures mediate distinctive or overlapping aspects of a complex behavioral process that has been associated with both neural sites, i.e. cognitive flexibility. Patients with focal ischemic lesions to the frontal lobe and basal ganglia were compared on two forms of cognitive flexibility: (1) shifting response set (i.e. reactive flexibility), and (2) producing a diversity of ideas (i.e. spontaneous flexibility). Results indicated that frontal lobe and basal ganglia damage each caused a similar degree of impairment in reactive flexibility, both groups performing at a significantly lower level than posterior cortical lesion and normal comparison groups. However, frontal lobe damage markedly disturbed spontaneous flexibility, while performance after basal ganglia lesion was significantly higher and comparable to posterior cortical lesions. Findings suggest that the frontal lobe and basal ganglia participate differently in the neural substrate of cognitive flexibility. The frontal lobe appears to mediate spontaneous flexibility. The production of diverse ideas may require direct cortical-cortical interactions by the frontal lobe in order to access knowledge systems with novel strategies that transcend the most common semantic linkages. In contrast the corticostriate system appears to mediate reactive flexibility, as the frontal lobe, basal ganglia and their interconnections are required for its operation.

Adult↗

A study of the relationship between the seizure focus and 1H-MRS in temporal lobe epilepsy and frontal lobe epilepsy.

Several studies of temporal lobe epilepsy (TLE) patients have investigated the relationship between the seizure focus and 1H magnetic resonance spectroscopy (1H-MRS). There have also been a few reports in other types of partial epilepsy. We examined the relationship between the seizure focus and the reduction in N-acetylaspartate: creatine (NAA : Cr) ratio using 1H-MRS in both TLE and frontal lobe epilepsy (FLE) patients. We studied 21 patients with unilateral TLE and seven patients with unilateral FLE. We used a 1.5 Tesla magnetic resonance unit (Signa Horizon; General Electric). Approximately 15 x 15 x 20 mm3 voxel of interest (VOI) was placed over the anterior portion of the bilateral hippocampus in the TLE patients, and the anterodorsal position of bilateral frontal lobe in the FLE patients. The seizure focus was identified by interictal scalp electro-encephalogram (EEG). In the TLE patients the NAA : Cr ratios were reduced in the seizure focus, while in the FLE patients they were not always reduced in the seizure focus. In the TLE patients the coincidence rate between the seizure focus and the reduction in the NAA:Cr ratio was 90% (19 of 21 patients), while in the FLE patients the coincidence rate was only 57% (four of seven patients).

Adult↗

Psychiatry and the frontal lobes.

The frontal lobes of the brain have long been regarded as enigmatic in their function and perhaps should be considered even more so in states of dysfunction. Observed associations between structural lesions and psychiatric symptoms and the demonstration of disturbed function and morphology in the frontal lobes of individuals suffering from major psychiatric disorders have led to increased interest in this brain area. Psychiatrists have been particularly concerned with seeking the aetiogenesis of common diagnostic entities and this article attempts to synthesize the available facts. A brief overview of relevant biological data precedes a description of methods of neuropsychological testing and the clinical features arising from frontal lobe damage. A discussion of the role of the frontal lobes in some aspects of personality function follows. Neuropsychiatric features associated with known frontal lobe pathology are described, prefacing a discussion of those psychiatric conditions where an aetiological role for frontal lobe dysfunction has been proposed.

Brain Diseases↗

Is impairment in set-shifting specific to frontal-lobe dysfunction? Evidence from patients with frontal-lobe or temporal-lobe epilepsy.

Frontal-lobe epilepsy (FLE), temporal-lobe epilepsy (TLE), and matched-control subjects were administered the Trail Making Test (TMT) of the Delis-Kaplan Executive Function System (D-KEFS; Delis et al., 2001), which assesses set-shifting on a visuomotor sequencing task. Results indicated that patients with FLE were impaired in both speed and accuracy on the switching condition relative to patients with TLE and controls. The two patient groups did not differ from controls on the four baseline conditions of the test, which assess visual scanning, motor speed, number sequencing, and letter sequencing. In addition, seizure-related variables (i.e., age of seizure onset, duration of epilepsy, and seizure frequency) failed to correlate with set-shifting performance in patients with FLE. These results suggest that patients with FLE can be reliably distinguished from those with TLE and control subjects on set-shifting as measured by the DKEFS TMT.

Adult↗

Deficits in executive functions and motor coordination in children with frontal lobe epilepsy.

Frontal lobe dysfunction in adults has been associated with impairments of planning abilities, working memory, impulse control, attention and certain aspects of motor coordination. However, very few studies have attempted to assess these functions in children suffering from frontal lobe epilepsy. The aim of the present study was to determine whether some or all of the components of the frontal lobe syndrome are present in children with this disorder. For this purpose, a neuropsychological test battery was administered to 32 unresected epileptic children, aged 8-16 years: 16 with frontal lobe epilepsy (FLE), eight with temporal lobe epilepsy (TLE) and eight with generalized epilepsy whose principal manifestations were typical absences (GEA). The performances of the three epileptic groups were further compared to normative data derived from 200 French-speaking, healthy children aged 7-16 years, except for standardized tests for which the norms provided in the manual were used. The three epilepsy groups did not differ with respect to conceptual shift and recency memory. However, the FLE children showed deficits in planning and impulse control. Furthermore, they had significantly more coordination problems and exhibited greater rigidity than the other epilepsy groups on the motor tests. These problems were more marked in younger FLE children (8-12 years). The latter were also more impaired on verbal fluency measures. No differences were observed with respect to gender, localization of the epileptic abnormality (unilateral versus bilateral) or medication (monotherapy versus polytherapy). The findings reveal similarities between the neuropsychological profiles of FLE children and adults with frontal lobe lesions.

Adolescent↗

[Frontal lobe epilepsy in infancy: is there a benign partial frontal lobe epilepsy?].

INTRODUCTION: Only the organic and cryptogenic forms of frontal lobe epilepsy have been admitted by the ILAE, but according to several reports in the literature, it probably exists also an idiopathic form, at present not well recognized. OBJECTIVE: To study the differences between the organic and the cryptogenic forms of frontal epilepsy in our patients, that might indicate the presence of idiopathic cases within the presumed cryptogenic group. MATERIAL AND METHODS: All patients diagnosed of frontal lobe epilepsy, EEG registered, at the neuropediatric clinic of our hospital during 1993-1996, were selected: 30 patients under 14 years of age that were classified as organic (10 cases) or cryptogenic (20 cases) according to CT or MRI findings. The Mann-Whitney test and the Fisher exact test were performed for statistical analysis. Five patients with peculiar neurocognitive symptoms, epilepsy-related, are described in detail. RESULTS: Significative differences between the organic and cryptogenic forms of frontal lobe epilepsy were not found except for the tendency of cryptogenic EEG foci to spread beyond the frontal lobe, to generalize and to be associated with foci of other localizations. Epileptic status, either convulsive or not convulsive, were a frequent complication in both groups. CONCLUSIONS: The identification of an idiopathic form of frontal lobe epilepsy is difficult by its low prevalence as compared to the cryptogenic and organic forms, by the tendency of frontal seizures to become epileptic status, which predicts an intractable epilepsy, and by the clinical characteristics essential to frontal discharges: heterogeneity, frequent impairment of consciousness and specially the neurocognitive semiology, including dementia, that occurs as a critic or paracritic phenomenon, and that sometimes may develop or be accentuated by antiepileptic medication.

Anticonvulsants↗

Frontal lobe epilepsy.

Frontal lobe epilepsy accounts for only 10-20% of the patients in surgical series, but the incidence in non-surgical patient cohorts seems to be much higher. The typical clinical presentation of the seizures includes contralateral clonic movements, uni- or bilateral tonic motor activity as well as complex automatism. The yield of surface EEG may be limited due to the difficulty in detection of mesial or basal foci, and the patient may be misdiagnosed as having non-epileptic events. In addition, in patients with mesial frontal foci the epileptiform discharges may be mislateralized ("paradoxical lateralization"). Therefore, epilepsy surgery has been commonly considered as less promising in patients with frontal lobe epilepsy. However, the advent of sophisticated neuroimaging techniques, particularly MRI with epilepsy-specific sequences, has made it possible to delineate the epileptogenic lesion and detect a specific etiology, in an increasing number of patients. Thus, the success rate of epilepsy surgery in frontal lobe epilepsy is currently comparable to temporal lobe epilepsy, if the candidates are carefully selected. Patients with frontal lobe epilepsy who do not respond to anticonvulsive medication, and who are not eligible for epilepsy surgery may benefit from alternative approaches such as electrical brain stimulation.

Anticonvulsants↗